When considering the life to be expected from a structure before any major repairs are needed, it is important to remember that most structures are likely to require some maintenance during their service lives. This is especially true where structures are exposed to the demanding conditions of the natural environment as well as having to cope with often onerous ‘manmade’ loading. A structure could in particular circumstances be designed with a very limited life in view and with no provision for maintenance, but such structures are the exception rather than the rule.
D.A. Holland